if (document.images) {


	img50on = new Image();           
	img50on.src = "images/subbtn_overview_b.gif";  
	img51on = new Image();           
	img51on.src = "images/subbtn_benefits_b.gif";  
	img52on = new Image();           
	img52on.src = "images/subbtn_features_b.gif"; 
	img53on = new Image();           
	img53on.src = "images/subbtn_snapshots_b.gif"; 
	img54on = new Image();           
	img54on.src = "images/subbtn_requirements_b.gif"; 

	img50off = new Image();          
	img50off.src = "images/subbtn_overview_a.gif"; 
	img51off = new Image();          
	img51off.src = "images/subbtn_benefits_a.gif"; 
	img52off = new Image();          
	img52off.src = "images/subbtn_features_a.gif"; 
	img53off = new Image();          
	img53off.src = "images/subbtn_snapshots_a.gif"; 
	img54off = new Image();          
	img54off.src = "images/subbtn_requirements_a.gif";
}